The present invention relates generally to control valves and, in an embodiment described herein, more particularly provides a rotary control valve and control system particularly useful to control operation of well tools.
Space is at a premium in most downhole tools, due to the fact that flow and access must be accommodated while also allowing for the tool functions to be performed. In the past, most hydraulic control systems have used sliding sleeves, poppets, etc., with o-ring or other elastomer seals to selectively control fluid communication.
However, some of these prior control systems require dynamic sealing against the o-rings, which leads to wear and eventual failure of the seals. In addition, prior control systems have been bulky or complex in operation.
Therefore, it will be appreciated that it would be desirable to provide improvements in control systems.